There was an interesting development late last week when Special Counsel Robert Mueller hired Michael Dreeben, a deputy in the Office of the Solicitor General, to work part-time with his staff. The addition of Dreeben added someone with considerable criminal and appellate experience. However, Dreeben’s background also contains an interesting item that bears directly on the potential case against President Donald Trump. Dreeben argued in an unsuccessful appeal of the prosecution of Arthur Anderson where the Justice Department advanced a sweeping interpretation of obstruction of justice — an interpretation that I criticized as wildly overbroad. The interpretation resulted in a unanimous rejection of the Supreme Court. Given the call for a charge of obstruction against Trump (and the view of some of us that there remains considerable statutory barriers to such a charge), Dreeben’s addition should be a concern to the Trump defense team.